var timeConsuming = function() {
    var y = 1;
    for (let i = 0; i < 500000; i++) {
         y *= y;
         y -= y*(y-i);
    }
}
var time = performance.now();
var defaultTime = 20;
var timeoutID = 0;
var intervalID = 0;
var requestID = 0;

var funTimeout = function(prev) {
    timeConsuming();
    var time = performance.now();
    document.getElementById("text_timeout").innerText = "timeout:" + (time - prev).toString();
    timeoutID = setTimeout(funTimeout,defaultTime,time);
}

var funInterval = function() {
    timeConsuming();
    document.getElementById("text_interval").innerText = "interval:" + (performance.now() - time).toString();
    time = performance.now();
}

var funRequest = function(prev) {
    timeConsuming();
    var time = performance.now();
    document.getElementById("text_request").innerText = "request:" + (time - prev).toString();
    requestID = requestAnimationFrame(funRequest);
}

var startFunctions = function(){
    time = performance.now();
    timeoutID = window.setTimeout(funTimeout, defaultTime, time);
    intervalID = window.setInterval(funInterval, defaultTime);
    requestID = window.requestAnimationFrame(funRequest);
}

var stopFunctions = function(){
    clearInterval(intervalID);
    clearTimeout(timeoutID);
    cancelAnimationFrame(requestID);
}